Process for producing laurolactam from cyclododecanone

Abstract

Laurolactam having high quality is produced by reacting cyclododecanone with a hydroxylamine salt of a mineral acid, and converting the resultant cyclododecanoneoxime to laurolactam through the Beckmann rearrangement reaction, wherein a content of each of oxygen atom-containing C12 organic compounds, for example, cyclododecenone or epoxycyclododecane, and cycloaliphatic unsaturated C12 hydrocarbon compounds, contained, as an impurity, in the staring cyclododecanone material, is controlled to 1,000 ppm or less.

What is claimed is:  
     
       1. A process for producing laurolactam from cyclododecanone, comprising reacting cyclododecanone with a hydroxylamine salt of a mineral acid to prepare cyclododecanoneoxime, and converting the resultant cyclododecanoneoxime to laurolactam through the Beckmann rearrangement reaction, 
       wherein a content of each of the oxygen atom-containing organic compounds having 12 carbon atoms and cycloaliphatic unsaturated hydrocarbon compounds having 12 carbon atoms, contained, as an impurity, in the cyclododecanone used as a starting material, is controlled to 1,000 ppm or less.  
     
     
       2. The process for producing laurolactam as claimed in  claim 1 , wherein the total content of the oxygen atom-containing organic compounds having 12 carbon atoms and the cycloaliphatic unsaturated hydrocarbon compounds having 12 carbon atoms and respectively contained, as impurities, in the starting cyclododecanone material, is controlled to 2,000 ppm or less. 
     
     
       3. The process for producing laurolactam as claimed in  claim 1  or  2 , wherein the oxygen atom-containing organic compounds having 12 carbon atoms and contained, as impurities, in the starting cyclododecanone material include noncyclo-aliphatic hydrocarbon compounds and cycloaliphatic hydrocarbon compounds respectively having at least one carbonyl group per molecule thereof. 
     
     
       4. The process for producing laurolactam as claimed in  claim 1  or  2 , wherein the oxygen atom-containing organic compounds having 12 carbon atoms and contained, as impurities, in the starting cyclododecanone material include noncyclo-aliphatic hydrocarbon compounds and cycloaliphatic hydrocarbon compounds respectively having at least one epoxy group per molecule thereof. 
     
     
       5. The process for producing laurolactam as claimed in  claim 1  or  2 , wherein the oxygen atom-containing organic compounds having 12 carbon atoms and contained, as impurities, in the starting cyclododecanone material include noncyclo-aliphatic hydrocarbon compounds and cycloaliphatic hydrocarbon compounds respectively having at least one aldehyde group per molecule thereof. 
     
     
       6. The process for producing laurolactam as claimed in  claim 1  or  2 , wherein the oxygen atom-containing organic compounds having 12 carbon atoms and contained, as impurities, in the starting cyclododecanone material include noncyclo-aliphatic hydrocarbon compounds and cycloaliphatic hydrocarbon compounds respectively having at least one hydroxyl group per molecule thereof. 
     
     
       7. The process for producing laurolactam as claimed in  claim 1 , wherein a content of each of the oxygen atom-containing organic compounds having 12 carbon atoms and the cycloaliphatic unsaturated hydrocarbon compounds having 12 carbon atoms, and contained, as impurities, in the starting cyclododecanone material, is controlled to 500 ppm or less. 
     
     
       8. The process for producing laurolactam as claimed in  claim 1 , wherein the starting cyclododecanone material is pre-treated with an alkali metal hydroxide or toluenesulfonic acid at a temperature of 70 to 230° C. 
     
     
       9. The process for producing laurolactam as claimed in  claim 1 , wherein the starting cyclododecanone material is pre-treated with at least one member selected from solid acids and ion-exchange resins at a temperature of 70 to 230° C.